Broadband data and video services, on which our society and economy have grown to depend, have heretofore generally not been readily available to users on board mobile platforms such as aircraft, ships, trains, automobiles, etc. While the technology exists to deliver such services to all forms of mobile platforms, past solutions have been generally quite expensive, low data rate and/or available to only very limited markets of government/military users and some high-end maritime markets (i.e., cruise ships).
At present, a wide variety of broadcast television (TV) services are available to terrestrial users via satellite links. Such services include commercial Direct Broadcast Satellite (DBS) services (such as DirecTV® and EchoStar®) and custom video, such as rebroadcast video, over private Fixed Satellite Services (FSS) or Broadcast Satellite Services (BSS) satellites. The data services which can be provided via satellite link include all conventional Internet services (e.g., email, web browsing, NetMeeting, etc.), as well as virtual private networks (VPNs) for corporate and government customers.
Previously developed systems which have attempted to provide live TV and data services to mobile platforms have done so with only limited success. One major obstacle has been the high cost of access to such broadband data and video services. Another problem is the limited capacity of previously developed systems, which is insufficient for mobile platforms carrying dozens, or even hundreds, of individuals who each may be simultaneously requesting different channels of programming or different data services. Furthermore, presently existing systems are generally not readily scalable to address the demands of the traveling public.
Certain services currently available provide a limited subset of the above described services. One such service provides a narrow-bandwidth Internet connection to users on a mobile platform. Another service provides either TV broadcast services from available direct broadcast signals (i.e., EchoStar® and DirectTV®) or provides a custom TV broadcast signal through dedicated satellite links (i.e., Airshow7). However, no system or method presently exists for providing high speed (i.e., greater than 64 Kbps) data networking services to groups of users on mobile or remote platforms, let alone for providing such high-speed networking services together with video services.
There are several operational systems that provide limited Internet data services on commercial airlines and cruise ships. These systems are very limited in their link capability (primarily use communication links developed for telephony) and the service is very expensive (greater than about $1.00 per minute for voice connection). For these reasons, and in view of adherent limitations on the capacity of such systems, such systems have met with limited commercial success and acceptance.
Current operational systems generally use Inmarsat satellite communication links or terrestrial wireless communication links (i.e., the National Air Telephone System “NATS”) to achieve 2-way connectivity to mobile platforms. These connection forms have several drawbacks:
a limited connection bandwidth (typically less than 64 Kbps);
limited overall system capacity (due to limited frequency spectrum); and high expense.
Inmarsat operates in the L-band frequency spectrum, where there is very little bandwidth and capacity available for providing broadband services to the traveling public. NATS based solutions (i.e., GTE® Airfone7, AT&T® Claircom), familiar to domestic airline travelers who use seat back-mounted telephones, also provide very limited capacity because of operation at L-band. These systems also suffer from the additional problem that connectivity is only available over land.
Current mobile platform connection methods are inherently narrow band and restrict the flow of data to the point where common networking tasks are unbearably slow. Typically, this connectivity is achieved through the use of a standard computer telephone modem between the user's computer and the air-ground or ship shore telephony system. In this scenario, each user gets exclusive use of a full communications channel for the duration of his/her networking session and effectively prevents others from using that portion of the telephony system.
Another desirable service on a mobile platform is bi-directional video teleconferencing. However, providing a video teleconference service on a mobile platform is subject to connectivity challenges. For example, a video teleconference system on a mobile platform based on an ISDN system may be subject to frequent loss of connection. This is because a mobile platform, such as an airplane, may pitch and roll as the mobile platform moves. This movement may cause the antennas of the mobile platform to point away from the satellite being used which, in turn, causes the signal strength to drop. In an ISDN system, if the signal strength drops below a predetermined threshold signal level, the connection is lost. As a result, reliability of an ISDN-based video teleconference service may be less than desired for a commercially feasible service.
Another possible implementation of a bi-directional video teleconference service may be based on a network architecture, such as a wide area network like the Internet, that uses packet data. A video teleconference system based on a network architecture and installed on a mobile platform may not lose connection as often as an ISDN-based video teleconference system may lose connection. Instead, when signal strength of packet data communication drops, data rate slows. As a result, video teleconference images may be “jerky” or subject to “stop and go” presentation. Further, audio may be out of synchronization with video images. Finally, even if data rate is not subject to slowdown due to low signal strength, packets of video teleconference data may be put together slowly if the network system on the mobile platform is processing a large volume of packet data other than the video teleconference data.
As a result, there is an unmet need in the art for a method and system for video teleconference services on a mobile platform that provides reliable and robust connection and data rate independent of signal strength and processing demands placed on a network system by packet data other than video teleconference data.